The present invention relates to a light radiator for effectively diffusing and radiating light rays which have been transmitted through an optical cable or the like, outside of the optical conductor cable.
The present applicant has previously proposed various ways to focus solar rays or artificial light rays by the use of lenses or the like, and to guide the same into an optical conductor cable, thereby transmitting them onto an optional desired place. The solar rays or the artificial light rays transmitted and emitted in such a way are used in the photo-synthesis process and for illuminating or other like purposes, such as for example to promote the growth of plants.
However, in the case of utilizing the light energy for growing plants, the light rays transmitted through the optical conductor cable have directional characteristics. Supposing that the end portion of the optical conductor cable is cut off and the light rays are emitted therefrom, then the radiation angle for the focused light rays is, in general, equal to approximately 46.degree.. That is quite a narrow field. In the case of utilizing the light energy as described above, it is impossible to obtain a desirable amount of illumination by simply cutting off the end portion of the optical conductor cable and thereby letting the light rays emit therefrom.
Therefore, the present application has already proposed various kinds of light radiators capable of effectively diffusing the light rays which have been transmitted through them and for radiating the same rays for illuminating a desired area. The present invention extends the idea and, in particular aims at applying intensified light rays to a desired place and to keep the light source at a distance to plants and to move the light source back and forth in order to supply light rays over a wider area.